Switches and auto negotiation

While you can't tell what the switches port is set to, (Although there are lights on the front that should say what it is connected at.)

You can/should be able to set the speed manually.
Assuming that this is a win box, select your network adapter and press the configure button.

You should have several options for configuring the card.

I know this seems an ambiguous description. But w/o knowing the OS or the make of the NIC it is hard to describe.

Most of the newer pcs shipping with nics since about a couple of years ago are by default (in windows) automatically when setup choose auto-sense mode. Which means that when you boot the pc the nic once it finds the switch will ask the switch what it wants to connect at. Most switches, by default ship with all ports in auto-sense mode too. So what speed do they connect at. 100Mb/s Full duplex. In all the os's i have used you can force the nic to connect at lower speeds like 100 half-dup or 10-half or full and most times you dont even have to telnet to the switch and tell it(at least with Cisco) Nortel switches act funny sometimes, but thats what they get for buying Baynetworks. Anyways.

If you are having speed issues and are usingpretty current switches and nics I would look more to a physical problem or something on th pc that is running in the background and killing your resources. Or a routing problem if you are trying to connect to a resource accross your wan.

If your using a 5 year old switch though you might want to take a look at it. Or just unplug it and wait 30 seconds and plug it back in. Sometimes the arp cache can start getting corrupted, but more than likely its back at the pc.

Just my 2 cents

Rad